This invention relates generally to carriers for holding objects during processing and particularly to a rotatable carrier for holding kinescope faceplates during the application of the phosphors.
During the application of phosphors to the inside surface of kinescope faceplates the faceplates are held in rotatable carriers during movement between the various stations of a processing line. The faceplates remain in the carrier and move along the processing line while the various steps of the processing are performed at each of the stations. As an example, initially the faceplates are placed into carriers and are cleaned and dried at the beginning of the processing line. The faceplates move to the next station where a photosensitive aqueous slurry of one of the three color phosphors needed for color television is applied to the inside of the faceplate. Typically, in order to get a uniform coating of phosphor the faceplate is rotated and the phosphor slurry flows over the entire internal surface. The faceplate then advances to subsequent stations where the phosphor slurry is dried and otherwise processed. The faceplates are next removed from the processing line and exposed to light so that a selected portion of dried photosensitive phosphor slurry is exposed to the light. The faceplates are next put into carriers along another processing line and washed and dried to leave the desired pattern of phosphor. The processing steps are then repeated for another of the three colors of phosphor.
All kinescopes must go through the same processing steps irrespective of size and it, therefore, is preferable to have faceplates of all sizes processed along the same line. However, faceplates of different sizes require carriers of different sizes and consequently there is a need for a carrier which can be quickly removed from the line at one of the stations where the carrier does not rotate without shutting down the entire processing line. Also, because the faceplates rotate during some of the processing steps, it is necessary for the carriers to firmly hold the faceplates without dropping them while simultaneously applying a controlled pressure to avoid crushing them. The invention is directed to a rotatable carrier which fulfills these requirements.